Reflectance Pulse Oximetry for Blood Oxygen Saturation Measurement from Diverse Locations-A Preliminary Analysis

Blood oxygen saturation level (SpO 2 ) is a clinically accepted vital sign for patient care and diagnostics. Oximeters are widely used by people suffering from asthma, congestive heart failures and pulmonary disorders as part of their routine care. Transmittance and reflectance pulse oximeters play a pivotal role in patient care and clinical decision making. In this paper, we study the feasibility of using reflectance photo plethysmography (PPG) for SpO 2 monitoring from various measurement sites on body. A preliminary study was conducted in a clinical setting on 10 subjects with pulmonary disorders. Arterial blood gas (ABG) analysis was used as a reference measure in the study. An SpO 2 data acquisition platform was developed, which uses custom-made dual wavelength reflectance SpO 2 sensor probes, Nellcor ™ transmittance probe for beat to beat SpO 2 measurement. The preliminary analysis of beat to beat reflectance PPG signal from finger, forehead, wrist and chest concur well with the reference measurement and gives enough scope to measure SpO 2 from various measurement sites like finger, forehead, wrist and chest.